Queens Democratic Sen. Mike Gianaris on Tuesday said it was “a mistake” for Republicans to keep Dean Skelos the majority leader in the chamber.

Gianaris, the leader of the Democrats’ political and fundraising operation, wouldn’t say however whether Skelos could play a role in next year’s legislative races, or if he believes the Long Island district Skelos represents is now competitive as he fights federal corruption charges.

“I think all districts are competitive given the right circumstances,” Gianaris said. “We’ll look at the board next year, but that’s eons away.”

Senate Republicans left a meeting late last night to affirm their “consensus” support for Skelos to remain on as leader, despite the charges.

“It’s a mistake, I can tell you that much,” Gianaris said, comparing the decision to back Skelos to other legislative conferences that have booted members after they were charged with corruption.

“Yet somehow in the Senate the Republicans now have an entire leadership in the Senate that’s under indictment and they go about business as usual,” Gianaris said.

Skelos himself has not been indicted as of it. Binghamton Sen. Tom Libous, the deputy majority, is under indictment for a charge of lying to the FBI.

Whether Skelos can effectively negotiate on behalf of the conference — especially when it comes to issues such as rent control, which Skelos is accused of placing undue influence on in 2011 by the federal complaint — remains an open question for Democratic lawmakers.

Gov. Andrew Cuomo himself is yet to publicly react to the latest corruption arrest to rock the Capitol.

Gianaris said it’s up to Cuomo as to whether the governor believes Skelos should be negotiating those key issues.

“I don’t think he should be the leader, so obviously I don’t think he’s capable of playing the role,” Gianaris said. “Whether the governor weighs in or not is his decision.”